<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    img {
      position: fixed;
      left: 0;
      bottom: 0;

    }
  </style>
</head>

<body>

  <img src="./images/ad.png" alt="">

  <script>
    const img = document.querySelector('img')
    setTimeout(function () {
      img.style.display = 'none'
    }, 3000)
  </script>
</body>

</html>